EP0508468A1 - Bohrer - Google Patents

Bohrer Download PDF

Info

Publication number
EP0508468A1
EP0508468A1 EP92106269A EP92106269A EP0508468A1 EP 0508468 A1 EP0508468 A1 EP 0508468A1 EP 92106269 A EP92106269 A EP 92106269A EP 92106269 A EP92106269 A EP 92106269A EP 0508468 A1 EP0508468 A1 EP 0508468A1
Authority
EP
European Patent Office
Prior art keywords
drill
insert
shank
cutting
accordance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP92106269A
Other languages
English (en)
French (fr)
Inventor
Kazuo c/o Itami Works of Sumitomo NOGUCHI
Yoshikatsu c/o Itami Works of Sumitomo MORI
Nagatoshi c/o Itami Works of Sumitomo Kunimori
Hideo c/o Itami Works of Sumitomo Mori
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Electric Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP3079058A external-priority patent/JPH05293710A/ja
Priority claimed from JP3079059A external-priority patent/JPH04315511A/ja
Priority claimed from JP3079057A external-priority patent/JPH04315510A/ja
Priority claimed from JP3079060A external-priority patent/JPH04315512A/ja
Priority claimed from JP083382U external-priority patent/JPH0534310U/ja
Priority claimed from JP091721U external-priority patent/JPH0541615U/ja
Application filed by Sumitomo Electric Industries Ltd filed Critical Sumitomo Electric Industries Ltd
Publication of EP0508468A1 publication Critical patent/EP0508468A1/de
Ceased legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B51/00—Tools for drilling machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B51/00—Tools for drilling machines
    • B23B51/02—Twist drills
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2251/00—Details of tools for drilling machines
    • B23B2251/48—Chip breakers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B2251/00—Details of tools for drilling machines
    • B23B2251/50—Drilling tools comprising cutting inserts
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S408/00—Cutting by use of rotating axially moving tool
    • Y10S408/713—Tool having detachable cutting edge
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/89—Tool or Tool with support
    • Y10T408/892—Tool or Tool with support with work-engaging structure detachable from cutting edge
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/89—Tool or Tool with support
    • Y10T408/905—Having stepped cutting edges
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/89—Tool or Tool with support
    • Y10T408/909—Having peripherally spaced cutting edges
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T408/00—Cutting by use of rotating axially moving tool
    • Y10T408/89—Tool or Tool with support
    • Y10T408/909—Having peripherally spaced cutting edges
    • Y10T408/9098—Having peripherally spaced cutting edges with means to retain Tool to support
    • Y10T408/90993—Screw driven means

Definitions

  • the present invention relates to the structure of a drill which is mainly employed for piercing, and more particularly, it relates to improvements in tip configuration, strength etc. of a drill, an improvement in structure of connection between an insert and a shank of a throw-away tipped drill, and the structure of a lock screw which is employed for fastening the insert to the shank.
  • a drill is one of cutting tools which are employed for piercing steel products or the like.
  • Fig. 1 shows an exemplary structure of a conventional twist drill 30.
  • This twist drill 30 is formed by a cutting portion 31 which is employed for piercing, and a shank 32, which concerns with no cutting but is mainly employed for discharging chips, to be mounted onto a chuck portion of a cutting machine such as a drilling machine.
  • Fig. 2 shows the forward end of such a twist drill 30.
  • a pair of cutting edges 33 are arranged on rotation-symmetrical positions with respect to the rotation axis of the drill 30. These cutting edges 33 linearly extend from ends of a chisel edge 34 toward the outer diametrical direction of the drill 30.
  • FIG. 3 shows another exemplary structure of a conventional spade drill 40.
  • This spade drill 40 is formed by a shank 41 and a cutting portion 42 which is fixed to the shank 41 by a mounting pin 43.
  • Fig. 4 shows the forward end of the cutting portion 42.
  • the cutting portion 42 of the spade drill 40 is provided in the form of a flat plate.
  • the forward end of this cutting portion 42 is formed by a pair of symmetrically provided cutting edges 44, which linearly extend from a central portion toward both ends of the cutting portion 42.
  • the drill 40 is further provided on its surfaces, serving as flanks, with slit-type nick portions 45 toward a direction substantially perpendicular to the cutting edges 44.
  • the cutting edges 33 and 44 which directly contribute to cutting of workpieces are linearly formed as shown in Figs. 2 and 4.
  • chips are continuously formed in widths corresponding to those of the linear cutting edges. Continuous formation of such wide chips leads to problems such as chip loading in a worked hole and chip winding on the drill.
  • the slit-type nick portions 45 are formed in the linear cutting edges 44 as shown in Fig. 4, to reduce the chip widths. Namely, the chips are parted through the nick portions 45, to be reduced in width. However, the chips thus reduced in width are diadvantageously increased in length since the same are liberated from the inner wall of the worked hole and a groove of the drill. Such long chips may cling to the drill, to extremely deteriorate chip controllability.
  • the worked hole may be loaded with the chips and chip controllability may be deteriorated by clinging of such chips.
  • chip loading disadvantageously causes breakage of the drill.
  • the conventional drill such as the twist drill shown in Fig. 1, for example, is provided with no chip breaker.
  • the spade drill shown in Fig. 3 may be provided with a chip breaker having a grinder, the application range of such a breaker is too narrow to attain a sufficient effect in practice.
  • a drill is an expendable item having a constant life due to wear or breakage in cutting work.
  • a drill such as the spade drill 40, in which only the cutting portion 42 is exchangeable, for example.
  • the cutting portion 42 of the conventional spade drill 40 is fixed by the mounting pin 43.
  • working accuracy may be reduced by a backlash in mounting, and the drill 40 may be broken due to insufficient mounting strength.
  • the conventional drill also has the following problem: As shown in Fig. 2 or 4, the drill is generally provided on its tip with a region called a chisel edge 34 or 46. Since such a chisel edge increases cutting resistance and receives a large thrust during cutting work, this portion may be ground out by thinning so that its edge width is reduced.
  • FIG. 5 is a plan view showing a cutting portion 51, which is thinned in a conventional method, of the drill developed by the inventors
  • Fig. 6 is a front elevational view showing the cutting portion 51.
  • a thinned surface 52 defined by the conventional thinning method is in the form of a curved surface along a cylindrical side surface from a chisel edge 53 toward a rear portion of the tip.
  • the width of the chisel edge 53 is defined by a radius R1 formed on the upper end of the thinned surface 52.
  • radius R1 roundness in a central portion of a tip 54 as well as the width of the chisel edge 53 are also increased, to deteriorate sharpness of the drill.
  • radius R1 is reduced, on the other hand, a radius R2 of the thinned surface 52 formed in the rear portion of the tip is also reduced although sharpness of the drill is improved, to define a relatively steep inflection surface in the rake face of the drill in the form of a groove.
  • stress concentration is caused in the vicinity of the thinned surface 52, to reduce strength of the drill.
  • An object of the present invention is to provide a drill having a tip configuration which is excellent in chip controllability, for preventing chip loading and clinging of chips to the drill.
  • Another object of the present invention is to provide a drill having a chip breaker, which is improved in chip controllability.
  • Still another object of the present invention is to provide a drill which is excellent in economy and has sufficient tool strength.
  • a further object of the present invention is to provide a drill subjected to thinning, which is improved in tip sharpness and capable of maintaining its strength.
  • a further object of the present invention is to provide a throw-away tipped drill having a structure which can prevent separation of an insert from a shank.
  • a further object of the present invention is to provide a throw-away tipped drill having a shank structure which can prevent chip loading during piercing.
  • a further object of the present invention is to provide a lock screw having a ball, which is suitably employed for ensuring connection between an insert and a shank of a throw-away tipped drill.
  • a drill according to the present invention is provided on its forward end with a pair of first and second cutting edges which extend substantially from the center of the rotation axis toward the outer diametrical direction of the drill to be arranged on rotation-symmetrical positions about the rotation axis.
  • Each of the first and second cutting edges has first and second linear cutting regions which are aligned with each other on the same straight line, and a curved cutting region which is formed between the first and second linear cutting regions.
  • the curved cutting region is so provided between the first and second linear cutting regions as to change chips from elongated flat plate forms to those corrugated in perpendicular sections along the longitudinal direction.
  • chips are friable and easily broken while the same are increased in deformation resistance.
  • the chips are finely crushed and prevented from loading in a worked hole and clinging to the drill.
  • a drill according to another aspect of the present invention is provided on its forward end with a pair of cutting edges which extend substantially from the center of the rotation axis toward the outer diametrical direction of the drill to be arranged on rotation-symmetrical positions about the rotation axis of the drill. Further, a rake face of the drill is provided with a projection for breaking chips.
  • the chips formed along the rake face are brought into contact with the projection which is provided on the rake face of the drill, so that the direction of chip formation is inflected.
  • the chips are brought into contact with the surface of a workpiece or the inner wall of the worked hole, to be finely broken. Therefore, it is possible to prevent formation of elongated chips and to suppress clinging of such chips to the drill.
  • a drill comprises an insert for cutting a workpiece and a shank to be mounted on a prescribed position of a cutting machine.
  • the shank is provided on its forward end with a cavity for receiving the insert and a holding portion for holding the same.
  • the insert is provided with a held portion which is received in and held by the cavity of the shank and a tip portion which has an outer diametrical width corresponding to the diameter of a hole to be worked and is provided on its forward end surface with a pair of cutting edges which are symmetrically formed about the rotation axis of the drill.
  • This insert is in the form of a substantially T-shaped flat plate as a whole. An angular portion connecting the held portion and the tip portion of the insert with each other is worked in the form of a circular arc.
  • the held portion is inserted into the cavity of the shank under pressure, so that the insert is fixed to the shank.
  • a position for mounting the insert onto the shank is automatically defined.
  • the angular portion between the held portion and the tip portion of the insert is worked in the form of a circular arc, whereby the angular portion is prevented from stress concentration caused by external force which is applied to the drill during cutting work, so that no cracking is caused.
  • a drill according to still another aspect of the present invention is provided on its forward end with a pair of cutting edges which extend substantially from the center of the rotation axis to be arranged on rotation-symmetrical positions about the rotation axis, and a thinned surface which is formed in a rake face in the vicinity of a chisel edge.
  • the thinned surface has a curved region along a truncated-conical side configuration which is supposed to be reduced in diameter toward the tip of the drill.
  • the thinned surface is formed in a configuration along the side surface of a truncated cone while the radius of curvature of the tip portion is reduced as compared with that of the rear portion of the tip, thereby satisfying the aforementioned conditions.
  • a throw-away tipped drill comprises an insert for cutting a workpiece, and a shank to be mounted on a prescribed position of a cutting machine.
  • the insert is separably mechanically connected to the shank. Further, the insert has a received portion to be received in the shank, which in turn has a holding portion for receiving and holding the received portion of the insert.
  • An engage member is provided between the insert and the shank to be engaged with the same, thereby preventing separation of the insert which is received in the shank.
  • the engage member comprises a cavity which is formed in the received portion of the insert and an engage piece which is formed in the holding portion of the shank to be engaged with the cavity of the insert.
  • This engage piece has a male screw which is screwed into a through screw hole provided in the holding portion of the shank, to press the surface of the cavity of the insert.
  • the insert and the shank are connected with each other by the engage member.
  • the engage member When external force acts in a direction for separating the insert from the shank, therefore, separation of the insert is prevented against such external force.
  • the shank has a chip discharge surface which is continuous to a rake face of the insert to axially extend along the shank.
  • the chip discharge surface is retracted from the rake face reversely to the rotational direction of the drill.
  • a lock screw according to the present invention which is suitable as engage means for the insert and the shank of tbe throw-away tipped drill, has a cylindrical configuration provided with a male screw on its outer peripheral surface and a washer groove on its forward end.
  • the washer groove is rotatably engageable with a ball, which is pressed against a fixed material.
  • the washer groove is provided in its bottom side with a tapered hole, which is rearwardly reduced in diameter, in continuation to the washer groove.
  • the washer groove is further provided on its forward end with an expanding slot, which circumferentially divides the washer groove and the tapered hole.
  • the ball is pushed into the tapered hole when the lock screw is screwed into a screw hole of a fixed portion to press a contact surface provided in the forward end of the ball against the counter material, whereby the washer groove provided in the forward end of the lock screw and the tapered hole are expanded in diameter due to a wedge effect, to come into pressure contact with the inner surface of the screw hole.
  • the lock screw is prevented from reverse rotation by frictional force which is caused in this pressure contact point, whereby natural looseness is eliminated.
  • the contact pressure between the lock screw and the inner surface of the screw hole is not increased until the ball strikes the counter material, so that the screw hole is not damaged. Further, the washer groove and the tapered hole are prevented from excess expansion since the screw hole serves as a regulating surface, whereby the male screw is not damaged even if excess screw torque is applied.
  • Fig. 7 is a front elevational view showing a throw-away tipped drill according to the first embodiment of the present invention
  • Fig. 8 is a left side elevational view thereof.
  • This throw-away tipped drill is formed by an insert 1 for cutting a workpiece such as a steel product, and a shank 20, which holds the insert 1, for mounting the drill onto a cutting tool.
  • Fig. 9 is an exploded perspective view showing a method of connecting the insert 1 with the shank 20. Referring to Fig. 9, held surfaces 2 of the insert 1 are brought into contact with holding portions 21 of the shank 20, so that the insert 1 is fixed to the shank 20 by the resulting frictional force.
  • Such a connection system for the insert 1 and the shank 20 is called a self-grip system.
  • Figs. 10, 11, 12 and 13 are a front elevational view, a plan view, a bottom plan view and a left side elevational view showing the insert 1 respectively.
  • Figs. 14A, 14B, 14C and 14D are sectional views taken along the lines A - A, B - B, C - C and D - D in Fig. 10 respectively.
  • the insert 1 is formed by a tip portion 15 which is provided with cutting edges 4 and a held portion 16 which is held by the holding portions 21 of the shank 20, as a substantially T-shaped flat plate.
  • the tip portion 15 is provided with flanks 6 of the drill on its forward end surface and with rake faces 7 of the drill on its side portions.
  • a pair of cutting edges 4 of the drill are formed along intersection lines between the flanks 6 and the rake faces 7.
  • the pair of cutting edges 4 are arranged on rotation-symmetrical positions about the rotation axis of the drill passing through the center of a chisel edge 3.
  • Fig. 15 is a plan view showing the configurations of the cutting edges 4.
  • Each of the cutting edges 4 is formed by a first linear cutting region 4a, a curved cutting region 4c and a second linear cutting region 4b successively from the center of the chisel edge 3 toward the outer diametrical region of the drill.
  • a cutting central region 4d is formed by thinning between the first linear cutting region 4a and the chisel edge 3.
  • the first and second linear cutting regions 4a and 4b are aligned with each other on the same straight line.
  • the pairs of first and second linear cutting regions 4a and 4b are in parallel with each other.
  • the curved cutting regions 4c have third linear cutting regions 4e and 4f respectively.
  • the third linear cutting regions 4e and 4f intersect with the second linear cutting regions 4b at an intersection angle ⁇ respectively. Both end portions of the third linear cutting regions 4e and 4f are connected to the first and second linear cutting regions 4a and 4b through smooth curved regions.
  • the respective curved cutting regions 4c of the pair of cutting edges 4 are in configurations which are different from each other with different widths, for example. Referring to Fig. 15, widths L2 and L3 of the pair of curved cutting regions 4c are different from each other. As to the configurations of the cutting edges 4, preferable sizes of the respective regions obtained through various experiments are described later.
  • the pair of cutting edges 4 are provided with the curved cutting regions 4c, to form chips in configurations following those of the cutting edges 4. Such chips are easily broken when the same come into contact with the drill or the inner wall of a worked hole. Thus, the chips are finely broken, and chip controllability is improved.
  • Fig. 16 is a plan view showing a modification of the cutting edges 4. Curved cutting regions 4c of the cutting edges 4 shown in Fig. 16 are provided with curved regions 4g and 4h, which are formed by parts of circular arcs having radii R, in place of the third linear cutting regions 4e and 4f shown in Fig. 15.
  • Fig. 17 is a plan view showing another modification of the cutting edges 4.
  • Each of the cutting edges 4 shown in Fig. 17 has two curved cutting regions and three linear cutting regions.
  • the configurations shown in Fig. 15 or 16 can be applied to the plurality of curved cutting regions.
  • nick portions are now described. Referring to Figs. 10, 11 and 15 to 17, slot-shaped nicks 5 are formed in the flanks 6 of the insert 1 to extend from the curved cutting regions 4c along the surfaces of the rake faces 7. Referring to Fig. 15, for example, the nicks 5 are so provided in the curved cutting regions 4c that chips formed by the first and second linear cutting regions 4a and 4b are divided through the nicks 5 along the directions of formation thereof, and discharged. Thus, it is possible to reduce the chip widths.
  • Chip breakers of the insert 1 of the drill shown in Fig. 10 are now described.
  • the insert 1 is provided on its side surfaces with chip breaking surface 8 in continuation to the rake faces 7.
  • each chip breaking surface 8 is formed in constant inclination with respect to each rake face 7.
  • each rake face 7 is provided with first chip breakers 9a which are formed by two spherical projections, while each chip breaking surface 8 is provided with a second chip breaker 9b formed by a spherical projection which is larger than the first chip breakers 9a.
  • thinned surfaces 10 are formed in rake face sides of the pair of cutting central regions 4d about the center of the chisel edge 3.
  • the thinned surfaces 10 define parts of a side surface of a cone whose projecting end is directed toward the center of the chisel edge 3.
  • Such thinned configurations, defining parts of the side surface of the cone are adapted to reduce curvatures of the cutting central regions 4d in the chisel sides while reducing the chisel width, thereby improving sharpness of the drill. Further, curvatures of tip rear sides are increased to improve strength of the insert 1.
  • the held portion 16 is held between the holding portions 21 of the shank 20 by a wedge effect, so that the insert 1 is fixed to the shank 20.
  • Upper and lower surfaces 13 of the insert 1, which is fixed to the shank 20, are supported by support surfaces 21a of the holding portions 21 of the shank 20.
  • a thrust which is applied in cutting work from the forward end of the insert 1 to the center of the rotation axis is received by the support surfaces 21a of the shank 20. Namely, the thrust is applied to the insert 1 against a portion in proximity to the center of the rotation axis substantially passing through the center of the chisel edge 3, and support reactive force is applied to the upper and lower surfaces 13 as reactive force of the thrust.
  • a throat 11 between the tip portion 15 and the held portion 16 may be cracked by stress concentration. Therefore, the throat 11 is provided with a radius R t of curvature, while the holding portions 21 of the shank 20 are also curved in positions corresponding to the throat 11.
  • Figs. 18 and 19 show the results of a drill performance test for perforating workpieces by the drill shown in Figs. 10 and 15 while changing the sizes of the respective portions of each cutting edge 4.
  • Fig. 18 shows correlation between the various parameters L1 to L3 and ⁇ defining the configuration of each cutting edge 4 shown in Fig. 15. As shown in Fig. 18, it has been proved that the configuration of a cutting edge which exhibits excellent chip controllability resides in a region I. Referring to Fig.
  • ratios L2/L1 and L3/L1 of the first linear cutting region 4a to the second linear cutting region 4b are in a range of 1/3 to 2 and the angle ⁇ formed by the third linear cutting region 4e or 4f and the second linear cutting region 4b is in a range of 5 to 40°.
  • Fig. 19 shows configurations of chips formed in this region I and those in regions II to IV in Fig. 18. It is clearly understood that chips are finely broken by the drill in the region I as compared with those in other regions.
  • Fig. 20 shows the configurations of samples employed in such a comparison test, and Table 1 shows test conditions.
  • Feed Rate f 0.05 to 0.15 mm/rev.
  • Figs. 21, 22 and 23 show the configurations of chips resulting from such perforation respectively. It is understood from these figures that the chips formed in the inventive sample A were broken in shorter lengths than those in the conventional samples with narrower widths. It is also understood that such chips cause no loading nor clinging to the drill during perforation. This is also clarified in comparison of drills as to cutting power.
  • Figs. 24A, 24B, 25A and 25B are illustrative of cutting power lines showing time changes in cutting power of the inventive sample A and the conventional sample C.
  • Figs. 24A and 24B show the inventive sample A
  • Figs. 25A and 25B show the conventional sample C
  • cutting power was increased with time in the conventional sample C.
  • the inventive sample C exhibits substantially constant cutting power in relation to the time lapse in perforation.
  • the drill according to the first embodiment of the present invention is provided with linear cutting regions and curved cutting regions to finely break chips, whereby it is possible to prevent breakage of the drill as well as reduction in its throughput which may be caused by loading or clinging of chips, thereby improving chip controllability.
  • Fig. 26 is a sectional view showing tip configurations in a section substantially perpendicular to the direction of extension of cutting edges in a tip portion of an insert 1. Referring to Fig. 26, a first chip breaker 9a and a second chip breaker 9b are virtually aligned in the same section. A drill rake face 7 is inclined at an angle ⁇ with respect to a reference line 50 which is parallel to the rotation axis of the drill.
  • the first chip breaker 9a is provided in the form of a hemisphere having a radius R1 in a position separated from a cutting edge 4 by a distance L1. A projecting end thereof is retracted from the reference line 50 by a distance a1.
  • the second chip breaker 9b is provided in the form of a hemisphere having a radius R2 in a position separated from the cutting edge 4 by a distance L2. A projecting end thereof projects beyond the reference line 50 by a distance a2.
  • a chip breaking surface 8 which is reversely inclined with respect to the inclination of the rake face 7 is formed behind the second chip breaker 9b.
  • Figs. 27 and 28 are adapted to illustrate the functions of the chip breakers in relation to the drill which is driven at different feed rates. As shown in Fig. 27, each chip 26 is bent by the first chip breaker 9a in a low feed region under a feed rate f of 0.01 to 0.2 mm/rev., and cut into a fine chip 26a.
  • each chip 26 comes into contact with the second chip breaker 9b beyond the first chip breaker 9a in an intermediate or high feed region under a feed rate f of 0.1 to 0.6 mm/rev., curved by the second chip breaker 9b, and cut into a chip 26a which is slightly larger than that shown in Fig. 27.
  • the chip breakers 9a and 9b are so provided that the chips come into contact with the surfaces thereof, whereby constant resistance between the chips and the rake face of the drill is reduced to reduce overall cutting resistance of the drill.
  • Fig. 30 shows photographs of chips resulting from this cutting test. It is understood from Fig. 30 that chips formed by the inventive sample D are finely parted as compared with those formed by the comparative sample E having no chip breakers. The chips are more finely parted in a low feed region under a feed rate f of 0.05 to 0.1 mm/rev. by the function of the first chip breaker 9a having a small projection.
  • first chip breakers 9a and one second chip breaker 9b are provided with more chip breakers.
  • the first and second chip breakers may be linearly aligned with respect to the direction of chip formation.
  • the rake faces of the drill are provided with projections for breaking chips, whereby the chips are so finely parted that it is possible to prevent deterioration of chip controllability which may be caused by clinging or loading of such chips.
  • Fig. 31 is a graph of lines of stress showing the degrees of stress concentration caused in samples of such a throat 11 analyzed through a finite element method employing radii R t of the throat 11 as parameters, while illustrating an analysis model on its right end. From the results shown in Fig. 31, it is understood that stress concentration at the throat 11 is relieved when the radius R t of curvature thereof exceeds 0.5 mm, to attain relatively flat stress distribution along an analysis position A. It is also understood that no remarkable change is caused in such a relieved state of the stress concentration when the radius R t of curvature exceeds 1 mm, for example.
  • Table 4 shows the results of the cutting test.
  • Sample Feed Rate mm/rev.
  • Thrust kgf 0.1 mm/rev. 0.2 mm/rev. 0.3 mm/rev. 0.4 mm/rev. (150 kgf) (300 kgf) (450 kgf) (600 kgf)
  • B O O X broken
  • Fig. 33 illustrates the configurations of cutting edges
  • Fig. 34 is a front elevational view showing the tip portion for illustrating the configurations of the thinned surfaces 10.
  • the thinned surfaces 10 are formed on rake-face sides of a pair of cutting central regions 4d along a chisel edge 3.
  • the thinned surfaces 10 are formed along the side surface of a truncated cone 17 which is so placed that its projecting end is toward the chisel edge 3.
  • Such thinned configurations using parts of the side surface of the truncated cone 17 are adapted to reduce curvatures of the cutting central regions 4d on the chisel edge sides while reducing a chisel width W, thereby improving sharpness of the drill. Further, the strength of the insert 1 is improved by increasing curvatures at the rear portions of the cutting edges.
  • the thinned surfaces defining the side surface of the truncated cone are formed with small and large radii of curvature on the forward and rear portions of the insert, thereby improving sharpness of the drill while ensuring strength of the tip portion.
  • This embodiment relates to means for preventing separation of the insert 1 from the shank 20 in the throw-away tipped drill shown in Figs. 7 to 9.
  • the shank 20 has regions called chip pockets 55 (see Fig. 8) for discharging chips.
  • Each chip pocket 55 forms a space enclosed by chip discharge surfaces 55a and 55b (see Fig. 9), so that the chips formed by the insert 1 are discharged along the chip pocket 55 in the axial direction of the shank 20.
  • the insert 1 may disadvantageously be separated from the shank 20 when the drill is extracted from a perforated workpiece or released from a state biting into a workpiece.
  • the insert 1 is not separated from the shank 20 during perforation since the insert 1, which is held by elastic force of the holding portions 21 of the shank 20, is subjected to reactive force from the workpiece to be pressed against the shank 20.
  • external force acts in such a direction that the insert 1 is separated from the shank 20
  • the aforementioned problem of separation is easily caused since the drill is not provided with a structure for sufficiently resisting against such external force.
  • each chip pocket 55 is substantially flush with each rake face 7 of the insert 1 to axially extend along the shank 20. Due to such structure of the chip pocket 55, the chips may cling to the outer periphery of the shank 20, to cause chip loading.
  • This embodiment is directed to a throw-away tipped drill which comprises means for solving such problems.
  • the structure of this embodiment is now described with reference to Figs. 35A to 42.
  • Fig. 35A is a front elevational view showing the throw-away tipped drill according to this embodiment
  • Fig. 35B is a partially fragmented view showing a part thereof in an enlarged manner
  • Fig. 36 is a plan view showing the throw-away tipped drill of Fig. 35A
  • Fig. 37 is a sectional view taken along the line III - III in Fig. 35A
  • Figs. 38 to 40 are a front elevational view, a plan view and a side elevational view showing an insert respectively.
  • Fig. 41 is a front elevational view showing a shank
  • Fig. 42 is a left side elevational view showing the shank.
  • a throw-away tipped drill 100 according to this embodiment comprises an insert 110, and a shank 130 which detachably holds the insert 110.
  • the insert 110 is formed by a tip portion 111 provided with cutting edges 113 and a held portion 112 which is held between holding portions 131a and 131b of the shank 130, as a substantially T-shaped flat plate.
  • the cutting edges 113 are arranged on rotation-symmetrical positions about the rotation axis of the drill 100.
  • a pair of rake faces 114 are provided with projecting chip breakers 115.
  • a throat of the insert 110 is provided with contact surfaces 116, which are supported when the insert 110 is connected to the shank 130.
  • a notch 118 is provided on one side surface of the held portion 112 of the insert 110.
  • a notched surface 118a is formed in the notch 118 in constant inclination with respect to the rotation axis of the drill 100. The function of this notched surface 118a is described later.
  • the shank 130 is provided with the pair of holding portions 131a and 131b, and another pair of holding portions 133a and 133b, which are perpendicular to the holding portions 131a and 131b, for holding the insert 110, in order to define an insert receiving space 132 for receiving the held portion 112 of the insert 110.
  • the upper surfaces of the holding portions 133a and 133b define support surfaces to be in contact with the contact surface 116 of the insert 110, thereby supporting the same.
  • Coolant supply holes 137 are formed in the forward ends of the pair of holding portions 131a and 131b.
  • the holding portion 133b is provided with a through screw hole 138 communicating with the insert receiving space 132.
  • First and second chip pockets 135 and 136 are provided along the axial direction of the shank 130. The structures of these chip pockets 135 and 136 are described later.
  • FIG. 35A to 37 the structure according to this embodiment for preventing separation of the insert 110 is now described.
  • a male screw 139 is screwed into the through screw hole 138, which is provided in the holding portion 133b of the shank 130.
  • the insert 110 is so connected to the shank 130 that its notched surface 118a faces the through screw hole 138.
  • a semispherical pressing member 140 is inserted between the male screw 139 and the notched surface 118a of the insert 110.
  • the notched surface 118a of the insert 110 is formed at a prescribed angle ⁇ 1 with respect to the rotation axis of the drill 100. This angle ⁇ 1 is set at 10 to 20°.
  • the male screw 139 is so screwed that component force F1 of pressing force F of the male screw 139 acts on the inclined notched surface 118a to press the insert 110 against the shank 130 along the rotational direction of the drill 100.
  • connection strength between the insert 110 and the shank 130 is increased.
  • the pressing member 140 comes into contact with the notched surface 118a of the insert 110 by suppressing force of the male screw 139 through the pressing member 140, thereby preventing the insert 110 from separation.
  • the notched surface 118a of the insert 110 is inclined at a prescribed angle ⁇ 2 with respect to a direction perpendicular to the longitudinal direction of the insert 110.
  • This angle ⁇ 2 is preferably set at about 3 to 10°.
  • Such an inclination angle ⁇ 2 of the notched surface 118a causes component force F2 of the tightening force F of the male screw 139, whereby the held portion 112 of the insert 110 is strongly pressed against the inner surfaces of the holding portions 131a and 131b of the shank 130, so that the connection strength between the insert 110 and the shank 130 is improved.
  • the pressing member 140 is not restricted to a semispherical form but may alternatively be in a spherical form. Further, the forward end of the male screw 139 may be directly brought into contact with the notched surface 118a of the insert 110, and the pressing member 140 may be omitted. Since such a separation preventing structure formed by the male screw 139 or the pressing member 140 is mainly adapted to prevent separation of the insert 110, it is not necessary to increase the pressing force of the male screw 139 against the notched surface 118a.
  • the drill 100 is provided with the first and second chip pockets 135 and 136 in the shank 130.
  • the first chip pocket 135 is formed along the axial direction of the shank 130 from the forward ends of the holding portions 131a and 131b, and each of its chip discharge surfaces 135a is formed by a part of a cylindrical surface having a constant curvature.
  • the second chip pocket 136 extends along the axial direction of the shank 130 to be substantially continuous to the rake faces 114 of the insert 110, and each of its chip discharge surfaces 136a is hollowed from each rake face 114 of the insert 110 in a direction reverse to the rotational direction of the drill 100.
  • the chip discharge surfaces 135a and 136a of the first and second chip pockets 135 and 136 have curved surfaces which are formed by parts of cylindrical side surfaces, while the chip discharge surface 136a of the second chip pocket 136 is twisted to be retracted in a direction reverse to the rotational direction of the drill 100.
  • the second chip pocket 136 is located in a position separated by a distance L from the forward end of the shank 130 along the rotation axis (see Fig. 36). This distance L is preferably about 0.5 times to twice the drill diameter.
  • Figs. 43 and 44 illustrate fluctuations of required power in the inventive drill having chip pockets of two stages and a conventional drill having a chip pocket of one stage. It is clearly understood from Figs. 43 and 44 that only small fluctuation of the required power is caused by chip loading in the inventive drill.
  • engage means for preventing separation of the insert is provided between the insert and the shank, whereby it is possible to prevent separation of the insert when the drill is extracted from a workpiece upon perforation.
  • the chip discharge surfaces continuous to the rake faces of the insert are retracted in a direction opposite to the rotation axis of the drill, whereby it is possible to smoothly discharge the chips for preventing chip loading.
  • This embodiment relates to an improvement in a lock Screw which is employable as engage means for the fifth embodiment.
  • the structure of the lock screw according to this embodiment is now described with reference to Figs. 45 to 47.
  • a ball 63 is rotatably engaged in a washer groove 62 which is provided in a front surface of a lock screw 61, while the outlet of the washer groove 62 is slightly narrowed to prevent displacement of the ball 63.
  • a tapered hole 64 is formed on a bottom side of the washer groove 62 to be rearwardly reduced in diameter, so that a spherical surface of the washer groove 62 which is left on the inlet side of this hole 64 receives the ball 63 when the same is not loaded.
  • the lock crew 61 is provided with an expanding slot 65, which longitudinally extends from its front surface to the portion provided with the tapered hole 64, to circumferentially divide the forward end of the lock screw 61 into a plurality of parts.
  • the lock screw 61 has a small diameter, its forward end may sufficiently be divided into two parts. If the lock screw 61 has a large diameter, on the other hand, it is preferable to increase the number of expanding slots to facilitate elastic formation of the forward end of the lock screw 61.
  • a head portion 67 may be provided on the rear part of the lock screw 61 as shown in Fig. 46 in a non-circular form such as a polygonal form, for example, so that the lock screw 61 is driven by a spanner.
  • the ball 63 may be provided with a flat contact surface 63a as shown in Fig. 45, or the same may be formed by a complete sphere as shown in Fig. 46, depending on the usage of the lock screw 61.
  • the lock screw 61 As shown in Fig. 47, the lock screw 61 according to this embodiment is screwed into a screw hole of a fixed portion 73 to fix a counter member 74 under pressure by the ball 63. At this time, the ball 63 is so pressed into the tapered hole 64 as to enlarge the diameter of the forward end of the screw 61, which is provided with the expanding slot 65, due to the resulting wedge effect, thereby bringing the same into contact with the inner surface of the screw hole.
  • strong frictional force is caused between the outer periphery of the forward end of the lock screw 61 and the inner surface of the screw hole after the lock screw 61 is fastened, to prevent looseness which may be caused by vibration or the like, thereby maintaining the counter member in a stable fixed state.
  • the ball provided on its forward end serves as a wedge to enlarge the diameter of the forward end thereby attaining self locking due to frictional force which is caused between the lock screw and the screw hole.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Drilling Tools (AREA)
EP92106269A 1991-04-11 1992-04-10 Bohrer Ceased EP0508468A1 (de)

Applications Claiming Priority (12)

Application Number Priority Date Filing Date Title
JP79059/91 1991-04-11
JP3079058A JPH05293710A (ja) 1991-04-11 1991-04-11 ドリル
JP3079059A JPH04315511A (ja) 1991-04-11 1991-04-11 ドリル
JP79058/91 1991-04-11
JP79060/91 1991-04-11
JP3079057A JPH04315510A (ja) 1991-04-11 1991-04-11 ドリル
JP3079060A JPH04315512A (ja) 1991-04-11 1991-04-11 ドリル
JP79057/91 1991-04-11
JP83382/91 1991-10-15
JP083382U JPH0534310U (ja) 1991-10-15 1991-10-15 ロツクねじ
JP91721/91 1991-11-08
JP091721U JPH0541615U (ja) 1991-11-08 1991-11-08 スローアウエイ式ドリル

Publications (1)

Publication Number Publication Date
EP0508468A1 true EP0508468A1 (de) 1992-10-14

Family

ID=27551447

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92106269A Ceased EP0508468A1 (de) 1991-04-11 1992-04-10 Bohrer

Country Status (3)

Country Link
US (1) US5338135A (de)
EP (1) EP0508468A1 (de)
KR (1) KR950014986B1 (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996011079A1 (de) * 1994-10-07 1996-04-18 Kennametal Hertel Ag Werkzeuge + Hartstoffe Bohrer mit einem bohrspitzenteil
US5868533A (en) * 1994-08-01 1999-02-09 Fiala; Stanislav Finishing tool for precision machining of holes
EP0985476A1 (de) * 1998-08-13 2000-03-15 Sandvik Aktiebolag Wendelbohrer
EP1210196A1 (de) * 1998-08-21 2002-06-05 Allied Machine & Engineering Corp. Bohrer für bohrungen mit flachem grund
WO2002078887A1 (en) * 2001-03-28 2002-10-10 Allied Machine & Engineering Corp. Drill insert geometry having chip splitting groove
WO2008046520A1 (de) * 2006-10-13 2008-04-24 Kennametal Inc. Bohrerspitze für ein bohrwerkzeug
US7832966B2 (en) 2003-01-30 2010-11-16 Kennametal Inc. Drill for making flat bottom hole
US7947713B2 (en) 2000-10-30 2011-05-24 Janssen Pharmaceutica N.V. Tripeptidyl peptidase inhibitors
CN101511512B (zh) * 2006-10-13 2012-04-04 钴碳化钨硬质合金公司 用于钻孔工具的钻尖
DE202011050277U1 (de) 2011-05-30 2012-07-04 Gerhard Bockholt Bohrwerkzeug
WO2018114191A1 (en) * 2016-12-23 2018-06-28 Walter Ag A ball nose end mill insert, a ball nose end mill tool body and a ball nose end mill

Families Citing this family (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE511429C2 (sv) 1996-09-13 1999-09-27 Seco Tools Ab Verktyg, skärdel, verktygskropp för skärande bearbetning samt metod för montering av skärdel till verktygskropp
IL120948A0 (en) * 1997-05-29 1997-09-30 Iscar Ltd Cutting tool assembly
US5957635A (en) * 1998-08-21 1999-09-28 Allied Machine & Engineering Corp. Drill tool assembly
US6270297B1 (en) * 2000-01-28 2001-08-07 Ati Properties, Inc. Cutting tools and drill inserts with chip control geometry
JP4558884B2 (ja) * 2000-03-31 2010-10-06 京セラ株式会社 ドリル用スローアウェイチップおよびドリル
US7220083B2 (en) 2003-10-15 2007-05-22 Tdy Industries, Inc. Cutting insert for high feed face milling
US8637127B2 (en) 2005-06-27 2014-01-28 Kennametal Inc. Composite article with coolant channels and tool fabrication method
US20070036622A1 (en) * 2005-08-12 2007-02-15 Yg-1 Co., Ltd. Spade drill insert
US7687156B2 (en) 2005-08-18 2010-03-30 Tdy Industries, Inc. Composite cutting inserts and methods of making the same
BRPI0710530B1 (pt) 2006-04-27 2018-01-30 Kennametal Inc. Brocas de perfuração de solo cortadoras fixas modulares, corpos de broca de perfuração de solo cortadora fixa modular e métodos relacionados
JP5330255B2 (ja) 2006-10-25 2013-10-30 ティーディーワイ・インダストリーズ・エルエルシー 改良された耐熱亀裂性を有する物品
US7905687B2 (en) * 2007-01-16 2011-03-15 Tdy Industries, Inc. Cutting insert, tool holder, and related method
IL186967A0 (en) * 2007-10-28 2008-02-09 Iscar Ltd Cutting head of a reamer
US7905689B2 (en) * 2008-05-07 2011-03-15 Tdy Industries, Inc. Cutting tool system, cutting insert, and tool holder
US8790439B2 (en) 2008-06-02 2014-07-29 Kennametal Inc. Composite sintered powder metal articles
US8025112B2 (en) 2008-08-22 2011-09-27 Tdy Industries, Inc. Earth-boring bits and other parts including cemented carbide
US7976250B2 (en) * 2009-02-12 2011-07-12 Tdy Industries, Inc. Double-sided cutting inserts for high feed milling
US8491234B2 (en) 2009-02-12 2013-07-23 TDY Industries, LLC Double-sided cutting inserts for high feed milling
US9586264B2 (en) * 2009-04-28 2017-03-07 Kennametal Inc. Double-sided cutting insert for drilling tool
US8272816B2 (en) 2009-05-12 2012-09-25 TDY Industries, LLC Composite cemented carbide rotary cutting tools and rotary cutting tool blanks
US8308096B2 (en) 2009-07-14 2012-11-13 TDY Industries, LLC Reinforced roll and method of making same
US9643236B2 (en) 2009-11-11 2017-05-09 Landis Solutions Llc Thread rolling die and method of making same
US8807884B2 (en) * 2009-12-18 2014-08-19 Kennametal Inc. Tool holder for multiple differently-shaped cutting inserts
US9457412B2 (en) 2009-12-28 2016-10-04 The Board Of Trustees Of The University Of Alabama For And On Behalf Of The University Of Alabama Fabrication method for diamond film coating of drill bit
JP5051801B2 (ja) 2011-03-03 2012-10-17 株式会社ビック・ツール ドリル
US8800848B2 (en) 2011-08-31 2014-08-12 Kennametal Inc. Methods of forming wear resistant layers on metallic surfaces
US9016406B2 (en) 2011-09-22 2015-04-28 Kennametal Inc. Cutting inserts for earth-boring bits
US9011049B2 (en) 2012-09-25 2015-04-21 Kennametal Inc. Double-sided cutting inserts with anti-rotation features
US9283626B2 (en) 2012-09-25 2016-03-15 Kennametal Inc. Double-sided cutting inserts with anti-rotation features
US9879483B2 (en) * 2014-11-07 2018-01-30 Drebo Werkzeugfabrik Gmbh Drill head insert or drill head attachment and drill
CN109311103B (zh) 2016-06-13 2019-11-05 三菱瓦斯化学株式会社 钻头和孔形成方法
EP3305448B1 (de) 2016-09-23 2020-11-04 Milwaukee Electric Tool Corporation Lochsägen-dorn-anordnung
US10730119B2 (en) 2017-01-06 2020-08-04 Milwaukee Electric Tool Corporation Hole saw
US20180221967A1 (en) * 2017-02-06 2018-08-09 Allied Machine & Engineering Corp. Drilling system and drill insert and methods for hole drilling
USD973733S1 (en) 2017-08-15 2022-12-27 Milwaukee Electric Tool Corporation Hole saw

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2317989A1 (fr) * 1975-07-14 1977-02-11 Amtel Inc Outil a forer a pointe
DE2646528A1 (de) * 1976-10-15 1978-04-20 Guenther Hertel Bohrstange mit schneideinsatz, insbesondere flachbohrer
WO1989008520A1 (en) * 1988-03-14 1989-09-21 Greenfield Industries, Inc. Twist drill

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US930436A (en) * 1908-02-10 1909-08-10 Walker Brothers Wigan Ltd Boring-tool.
GB123605A (en) * 1918-03-05 1919-03-05 Vickers Ltd Improvements in or relating to Boring Tools.
US2237901A (en) * 1938-10-07 1941-04-08 William A Chun Drill
GB519475A (en) * 1938-10-18 1940-03-28 Thomas Alexander Forsyth Improvements in and relating to drilling tools
US2360385A (en) * 1941-03-08 1944-10-17 Blackhawk Mfg Co Drill
US2400856A (en) * 1943-07-16 1946-05-21 Pipe Machinery Company Cutting tool
US2621548A (en) * 1948-06-02 1952-12-16 Warren W Williams Mounting for cutting tools
DE2654400B2 (de) * 1976-12-01 1979-04-12 Udo 6384 Schmitten Prasche In einen Bohrhalter einsetzbares Bohrmesser
DE3204210C2 (de) * 1982-02-08 1986-04-03 Stellram GmbH, 6056 Heusenstamm Bohrwerkzeug für metallische Werkstoffe
DE3306209C2 (de) * 1983-02-23 1985-02-28 Iscar Hartmetall GmbH, 7505 Ettlingen Bohrwerkzeug mit auswechselbarem Schneideinsatz
DD256466A1 (de) * 1987-01-26 1988-05-11 Pumpen & Verdichter Veb K Feineinstellung, insbesondere fuer langlochfraeser
US4984944A (en) * 1987-02-09 1991-01-15 Vermont American Corporation Drill bit blade for masonry and rock drill

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2317989A1 (fr) * 1975-07-14 1977-02-11 Amtel Inc Outil a forer a pointe
DE2646528A1 (de) * 1976-10-15 1978-04-20 Guenther Hertel Bohrstange mit schneideinsatz, insbesondere flachbohrer
WO1989008520A1 (en) * 1988-03-14 1989-09-21 Greenfield Industries, Inc. Twist drill

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5868533A (en) * 1994-08-01 1999-02-09 Fiala; Stanislav Finishing tool for precision machining of holes
CN1063373C (zh) * 1994-10-07 2001-03-21 克纳门特尔-赫特尔刀具及硬质材料股份有限公司 带一个钻头尖端部分的钻头
WO1996011079A1 (de) * 1994-10-07 1996-04-18 Kennametal Hertel Ag Werkzeuge + Hartstoffe Bohrer mit einem bohrspitzenteil
EP0985476A1 (de) * 1998-08-13 2000-03-15 Sandvik Aktiebolag Wendelbohrer
EP1210196A1 (de) * 1998-08-21 2002-06-05 Allied Machine & Engineering Corp. Bohrer für bohrungen mit flachem grund
EP1210196B1 (de) * 1998-08-21 2005-09-21 Allied Machine & Engineering Corp. Bohrer für bohrungen mit flachem grund
US7947713B2 (en) 2000-10-30 2011-05-24 Janssen Pharmaceutica N.V. Tripeptidyl peptidase inhibitors
WO2002078887A1 (en) * 2001-03-28 2002-10-10 Allied Machine & Engineering Corp. Drill insert geometry having chip splitting groove
US6565296B2 (en) 2001-03-28 2003-05-20 Allied Machine & Engineering Corp. Drill insert geometry having chip splitting groove
US7832966B2 (en) 2003-01-30 2010-11-16 Kennametal Inc. Drill for making flat bottom hole
WO2008046520A1 (de) * 2006-10-13 2008-04-24 Kennametal Inc. Bohrerspitze für ein bohrwerkzeug
CN101511512B (zh) * 2006-10-13 2012-04-04 钴碳化钨硬质合金公司 用于钻孔工具的钻尖
RU2452597C2 (ru) * 2006-10-13 2012-06-10 Кеннаметал Инк. Вершина сверла для сверлильного инструмента
US8550756B2 (en) 2006-10-13 2013-10-08 Kennametal Inc. Drill bit for drilling having at least two cutting edges, each with two cutting portions and a non-cutting portion between the two cutting portions
DE202011050277U1 (de) 2011-05-30 2012-07-04 Gerhard Bockholt Bohrwerkzeug
WO2018114191A1 (en) * 2016-12-23 2018-06-28 Walter Ag A ball nose end mill insert, a ball nose end mill tool body and a ball nose end mill

Also Published As

Publication number Publication date
KR950014986B1 (ko) 1995-12-21
US5338135A (en) 1994-08-16
KR920019458A (ko) 1992-11-19

Similar Documents

Publication Publication Date Title
EP0508468A1 (de) Bohrer
EP0181844B1 (de) Bohrer und zugehöriger Schneideinsatz
US6582164B1 (en) Roller twist drill
EP1310311B1 (de) Schneideinsatzspannmechanismus
EP1507616B1 (de) Bohrwerkzeugsatz
US5741095A (en) Cutting tool and insert therefor
KR100776555B1 (ko) 드릴링 공구 및 인덱서블 드릴 비트
EP0942799B1 (de) Fräser
EP1383622B1 (de) Bohreinsatzgeometrie mit spanspaltender kerbe
US20040037659A1 (en) Cutting insert with curved cutting edge
CA2412515C (en) Drilling tool
EP1551585B1 (de) Spornspitzenbohreinsatz
US4984943A (en) Drill with balanced inserts
EP0222317A1 (de) Wendeschneidplatte
US4770571A (en) Drill
US6135677A (en) Indexable end mill and indexable insert
CA2395479A1 (en) Indexable drill and cutting inserts therefor
JPH04315512A (ja) ドリル
JP2549711Y2 (ja) 止まり穴切削加工用タップ
JPH10235509A (ja) スローアウェイ式ドリル
JP2521507Y2 (ja) 改良ドリル
JPH10244412A (ja) 穴明け工具
JPH09290311A (ja) スローアウェイ式穴明け工具
JPH04315511A (ja) ドリル
JPH10235510A (ja) スローアウェイチップ

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT

17P Request for examination filed

Effective date: 19930330

17Q First examination report despatched

Effective date: 19931227

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19960727